Gas Line Pressure Testing: What It Is, When It Is Required, and What to Expect
July 5, 2026 · 4 min read · By Deep Dive Plumbing Maryland
A gas line pressure test is a safety verification procedure required after any gas line installation, repair, or modification in Maryland. Here is what it involves and when you need one.
When a Pressure Test Is Required
Frequently Asked Questions
What is a gas line pressure test?
A gas line pressure test (also called a gas pressure test or leak test) is a procedure used to verify the integrity of a gas piping system. The plumber or gas fitter pressurizes the gas line with air or nitrogen (not gas) and monitors the pressure over a set period. If the pressure holds steady, the system is leak-free. If pressure drops, there is a leak somewhere in the system that must be located and repaired.
When is a gas line pressure test required?
A gas line pressure test is required: after any new gas line installation, after any gas line repair or modification, when a gas line has been shut off for an extended period, when a gas leak is suspected, and as part of a home inspection or permit inspection. In Maryland, gas line work requires a permit and inspection, which includes a pressure test.
How long does a gas line pressure test take?
A standard gas line pressure test takes 30–60 minutes, including setup, pressurization, monitoring, and documentation. If a leak is found, additional time is needed to locate and repair it, then retest. The test is typically performed by the licensed plumber or gas fitter who did the installation or repair.
Can I test my gas line myself?
No — gas line pressure testing requires specialized equipment and a licensed gas fitter or plumber. Attempting to test or repair gas lines yourself is illegal in Maryland and extremely dangerous. If you suspect a gas leak, leave the house immediately and call 911 and your gas company.
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